Effect of tunicamycin on the biosynthesis of calreticulin and myeloperoxidase in HL-60 and PLB-985 cells. Biosynthesis using a 60-minute pulse label in either HL-60 (left) or PLB-985 (right) cells, immunoprecipitation with either anticalreticulin (CRT; upper panel) or antimyeloperoxidase (MPO; lower panel), SDS-PAGE, and fluorography were performed as in Fig 2 except that the cells were cultured in tunicamycin at the concentrations indicated. The apparent increased intensity of the calreticulin signal in PLB-985 cells treated with tunicamycin was not a consistent finding in other experiments.